function (sum_it_up) that takes any number of parameters and returns to sum

Question

How to write a function (sum_it_up) that takes any number of parameters and returns to sum?

For instance this should print 22:

total=sum_it_up(1,4,7,10)
print(total)

Solution:

def sum_it_up (a,b,c,d):
print("The total is {0}".format(a+b+c+d))

sum_it_up(1,4,7,10)
sum_it_up(1,2,0,0)

The above solution is missing the return statement. Any ideas? Thanks!

That solution isn't valid anyways, since it doesn't take "any number of parameters". And what specifically do you need help with in adding a return? — Carcigenicate, Feb 18 '18 at 01:17
Your proposed solution doesn't scale. What if I want to sum _five_ numbers? six? The requirements said "any number of parameters." **(1)** Look into [`*args`](https://stackoverflow.com/questions/3394835/args-and-kwargs) **(2)** Since I'm assuming you can't use the built-in `sum`, you need to formulate a way to sum a list of numbers (_hint_: you'll need a loop). — Christian Dean, Feb 18 '18 at 01:17
Suggested reading: https://stackoverflow.com/questions/919680/can-a-variable-number-of-arguments-be-passed-to-a-function https://stackoverflow.com/questions/7129285/why-would-you-use-the-return-statement-in-python — georg, Feb 18 '18 at 01:19

score 0 · Accepted Answer · answered Feb 18 '18 at 01:43

As @georg suggested, you should use *args to specify a function can take a variable number of unnamed arguments.

args feeds the function as a tuple. As an iterable, this can be accepted directly by Python's built-in sum. For example:

def sum_it_up(*args):
    print('The total is {0}'.format(sum(args)))

sum_it_up(1,4,7,10)  # The total is 22
sum_it_up(1,2,0,0)   # The total is 3

1 Answers1